Jens Axboe [Wed, 28 Jun 2017 14:09:45 +0000 (08:09 -0600)]
fs/fcntl: use copy_to/from_user() for u64 types
Some architectures (at least PPC) doesn't like get/put_user with
64-bit types on a 32-bit system. Use the variably sized copy
to/from user variants instead.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: c75b1d9421f8 ("fs: add fcntl() interface for setting/getting write life time hints") Signed-off-by: Jens Axboe <axboe@kernel.dk>
Julia Lawall [Tue, 27 Jun 2017 23:56:50 +0000 (17:56 -0600)]
drbd: Drop unnecessary static
Drop static on a local variable, when the variable is initialized before
any use, on every possible execution path through the function. The
static has no benefit, and dropping it reduces the code size.
The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@bad exists@
position p;
identifier x;
type T;
@@
static T x@p;
...
x = <+...x...+>
@@
identifier x;
expression e;
type T;
position p != bad.p;
@@
-static
T x@p;
... when != x
when strict
?x = e;
// </smpl>
The change in code size is indicates by the following output from the size
command.
before:
text data bss dec hex filename
67299 2291 1056 70646 113f6 drivers/block/drbd/drbd_nl.o
after:
text data bss dec hex filename
67283 2291 1056 70630 113e6 drivers/block/drbd/drbd_nl.o
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Tue, 27 Jun 2017 18:30:47 +0000 (12:30 -0600)]
block, bfq: update wr_busy_queues if needed on a queue split
This commit fixes a bug triggered by a non-trivial sequence of
events. These events are briefly described in the next two
paragraphs. The impatiens, or those who are familiar with queue
merging and splitting, can jump directly to the last paragraph.
On each I/O-request arrival for a shared bfq_queue, i.e., for a
bfq_queue that is the result of the merge of two or more bfq_queues,
BFQ checks whether the shared bfq_queue has become seeky (i.e., if too
many random I/O requests have arrived for the bfq_queue; if the device
is non rotational, then random requests must be also small for the
bfq_queue to be tagged as seeky). If the shared bfq_queue is actually
detected as seeky, then a split occurs: the bfq I/O context of the
process that has issued the request is redirected from the shared
bfq_queue to a new non-shared bfq_queue. As a degenerate case, if the
shared bfq_queue actually happens to be shared only by one process
(because of previous splits), then no new bfq_queue is created: the
state of the shared bfq_queue is just changed from shared to non
shared.
Regardless of whether a brand new non-shared bfq_queue is created, or
the pre-existing shared bfq_queue is just turned into a non-shared
bfq_queue, several parameters of the non-shared bfq_queue are set
(restored) to the original values they had when the bfq_queue
associated with the bfq I/O context of the process (that has just
issued an I/O request) was merged with the shared bfq_queue. One of
these parameters is the weight-raising state.
If, on the split of a shared bfq_queue,
1) a pre-existing shared bfq_queue is turned into a non-shared
bfq_queue;
2) the previously shared bfq_queue happens to be busy;
3) the weight-raising state of the previously shared bfq_queue happens
to change;
the number of weight-raised busy queues changes. The field
wr_busy_queues must then be updated accordingly, but such an update
was missing. This commit adds the missing update.
Instead move it to the callers. Those that either don't use bio_data() or
page_address() or are specific to architectures that do not support highmem
are skipped.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: don't set bounce limit in blk_init_allocated_queue
And just move it into scsi_transport_sas which needs it due to low-level
drivers directly derferencing bio_data, and into blk_init_queue_node,
which will need a further push into the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
For historical reasons we default to bouncing highmem pages for all block
queues. But the blk-mq drivers are easy to audit to ensure that we don't
need this - scsi and mtip32xx set explicit limits and everyone else doesn't
have any particular ones.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-map: call blk_queue_bounce from blk_rq_append_bio
This makes moves the knowledge about bouncing out of the callers into the
block core (just like we do for the normal I/O path), and allows to unexport
blk_queue_bounce.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
pktcdvd is a make_request based stacking driver and thus doesn't have any
addressing limits on it's own. It also doesn't use bio_data() or
page_address(), so it doesn't need a lowmem bounce either.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 18:03:06 +0000 (12:03 -0600)]
nvme: add support for streams and directives
This adds support for Directives in NVMe, particular for the Streams
directive. Support for Directives is a new feature in NVMe 1.3. It
allows a user to pass in information about where to store the data, so
that it the device can do so most effiently. If an application is
managing and writing data with different life times, mixing differently
retentioned data onto the same locations on flash can cause write
amplification to grow. This, in turn, will reduce performance and life
time of the device.
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 17:51:28 +0000 (11:51 -0600)]
btrfs: add support for passing in write hints for buffered writes
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 15:34:01 +0000 (09:34 -0600)]
xfs: add support for passing in write hints for buffered writes
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 15:32:37 +0000 (09:32 -0600)]
ext4: add support for passing in write hints for buffered writes
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 15:30:05 +0000 (09:30 -0600)]
fs: add support for buffered writeback to pass down write hints
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 17:01:22 +0000 (11:01 -0600)]
fs: add O_DIRECT and aio support for sending down write life time hints
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Mon, 26 Jun 2017 14:15:27 +0000 (08:15 -0600)]
blk-mq: expose write hints through debugfs
Useful to verify that things are working the way they should.
Reading the file will return number of kb written with each
write hint. Writing the file will reset the statistics. No care
is taken to ensure that we don't race on updates.
Drivers will write to q->write_hints[] if they handle a given
write hint.
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 27 Jun 2017 17:47:04 +0000 (11:47 -0600)]
fs: add fcntl() interface for setting/getting write life time hints
Define a set of write life time hints:
RWH_WRITE_LIFE_NOT_SET No hint information set
RWH_WRITE_LIFE_NONE No hints about write life time
RWH_WRITE_LIFE_SHORT Data written has a short life time
RWH_WRITE_LIFE_MEDIUM Data written has a medium life time
RWH_WRITE_LIFE_LONG Data written has a long life time
RWH_WRITE_LIFE_EXTREME Data written has an extremely long life time
The intent is for these values to be relative to each other, no
absolute meaning should be attached to these flag names.
Add an fcntl interface for querying these flags, and also for
setting them as well:
F_GET_RW_HINT Returns the read/write hint set on the
underlying inode.
F_SET_RW_HINT Set one of the above write hints on the
underlying inode.
F_GET_FILE_RW_HINT Returns the read/write hint set on the
file descriptor.
F_SET_FILE_RW_HINT Set one of the above write hints on the
file descriptor.
The user passes in a 64-bit pointer to get/set these values, and
the interface returns 0/-1 on success/error.
Sample program testing/implementing basic setting/getting of write
hints is below.
Add support for storing the write life time hint in the inode flags
and in struct file as well, and pass them to the kiocb flags. If
both a file and its corresponding inode has a write hint, then we
use the one in the file, if available. The file hint can be used
for sync/direct IO, for buffered writeback only the inode hint
is available.
This is in preparation for utilizing these hints in the block layer,
to guide on-media data placement.
/*
* writehint.c: get or set an inode write hint
*/
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#include <inttypes.h>
Rakesh Pandit [Tue, 27 Jun 2017 11:55:33 +0000 (14:55 +0300)]
lightnvm: if LUNs are already allocated fix return
While creating new device with NVM_DEV_CREATE if LUNs are already
allocated ioctl would return -ENOMEM which is wrong. This patch
propagates -EBUSY from nvm_reserve_luns which is correct response.
Fixes: ade69e243 ("lightnvm: merge gennvm with core") Reviewed-by: Frans Klaver <fransklaver@gmail.com> Signed-off-by: Rakesh Pandit <rakesh@tuxera.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Javier González [Mon, 26 Jun 2017 09:57:29 +0000 (11:57 +0200)]
lightnvm: pblk: fail gracefully on irrec. error
Due to user writes being decoupled from media writes because of the need
of an intermediate write buffer, irrecoverable media write errors lead
to pblk stalling; user writes fill up the buffer and end up in an
infinite retry loop.
In order to let user writes fail gracefully, it is necessary for pblk to
keep track of its own internal state and prevent further writes from
being placed into the write buffer.
This patch implements a state machine to keep track of internal errors
and, in case of failure, fail further user writes in an standard way.
Depending on the type of error, pblk will do its best to persist
buffered writes (which are already acknowledged) and close down on a
graceful manner. This way, data might be recovered by re-instantiating
pblk. Such state machine paves out the way for a state-based FTL log.
Javier González [Mon, 26 Jun 2017 09:57:28 +0000 (11:57 +0200)]
lightnvm: pblk: set mempool and workqueue params.
Make constants to define sizes for internal mempools and workqueues. In
this process, adjust the values to be more meaningful given the internal
constrains of the FTL. In order to do this for workqueues, separate the
current auxiliary workqueue into two dedicated workqueues to manage
lines being closed and bad blocks.
Javier González [Mon, 26 Jun 2017 09:57:27 +0000 (11:57 +0200)]
lightnvm: pblk: redesign GC algorithm
At the moment, in order to get enough read parallelism, we have recycled
several lines at the same time. This approach has proven not to work
well when reaching capacity, since we end up mixing valid data from all
lines, thus not maintaining a sustainable free/recycled line ratio.
The new design, relies on a two level workqueue mechanism. In the first
level, we read the metadata for a number of lines based on the GC list
they reside on (this is governed by the number of valid sectors in each
line). In the second level, we recycle a single line at a time. Here, we
issue reads in parallel, while a single GC write thread places data in
the write buffer. This design allows to (i) only move data from one line
at a time, thus maintaining a sane free/recycled ration and (ii)
maintain the GC writer busy with recycled data.
Javier González [Mon, 26 Jun 2017 09:57:23 +0000 (11:57 +0200)]
lightnvm: pblk: choose optimal victim GC line
At the moment, we separate the closed lines on three different list
based on their number of valid sectors. GC recycles lines from each list
based on capacity. Lines from each list are taken in a FIFO fashion.
Since the number of lines is limited (it corresponds to the number of
blocks in a LUN, which is somewhere between 1000-2000), we can afford
scanning the lists to choose the optimal line to be recycled. This helps
specially in lines with a high number of valid sectors.
If the number of blocks per LUN increases, we will consider a more
efficient policy.
Javier González [Mon, 26 Jun 2017 09:57:21 +0000 (11:57 +0200)]
lightnvm: pblk: simplify meta. memory allocation
smeta size will always be suitable for a kmalloc allocation. Simplify
the code and leave the vmalloc fallback only for emeta, where the pblk
configuration has an impact.
Javier González [Mon, 26 Jun 2017 09:57:20 +0000 (11:57 +0200)]
lightnvm: pblk: issue multiplane reads if possible
If a read request is sequential and its size aligns with a
multi-plane page size, use the multi-plane hint to process the I/O in
parallel in the controller.
Javier González [Mon, 26 Jun 2017 09:57:19 +0000 (11:57 +0200)]
lightnvm: pblk: delete redundant buffer pointer
After refactoring the metadata path, the backpointer controlling
synced I/Os in a line becomes unnecessary; metadata is scheduled
on the write thread, thus we know when the end of the line is reached
and act on it directly.
Javier González [Mon, 26 Jun 2017 09:57:18 +0000 (11:57 +0200)]
lightnvm: pblk: delete redundant debug line stat
Remove a legacy variable that helped verifying the consistency of the
run-time metadata for the free line list. With the new metadata layout,
this check is no longer necessary.
Javier González [Mon, 26 Jun 2017 09:57:17 +0000 (11:57 +0200)]
lightnvm: pblk: sched. metadata on write thread
At the moment, line metadata is persisted on a separate work queue, that
is kicked each time that a line is closed. The assumption when designing
this was that freeing the write thread from creating a new write request
was better than the potential impact of writes colliding on the media
(user I/O and metadata I/O). Experimentation has proven that this
assumption is wrong; collision can cause up to 25% of bandwidth and
introduce long tail latencies on the write thread, which potentially
cause user write threads to spend more time spinning to get a free entry
on the write buffer.
This patch moves the metadata logic to the write thread. When a line is
closed, remaining metadata is written in memory and is placed on a
metadata queue. The write thread then takes the metadata corresponding
to the previous line, creates the write request and schedules it to
minimize collisions on the media. Using this approach, we see that we
can saturate the media's bandwidth, which helps reducing both write
latencies and the spinning time for user writer threads.
Javier González [Mon, 26 Jun 2017 22:27:13 +0000 (16:27 -0600)]
lightnvm: pblk: rename read request pool
Read requests allocate some extra memory to store its per I/O context.
Instead of requiring yet another memory pool for other type of requests,
generalize this context allocation (and change naming accordingly).
Javier González [Mon, 26 Jun 2017 09:57:15 +0000 (11:57 +0200)]
lightnvm: pblk: generalize erase path
Erase I/Os are scheduled with the following goals in mind: (i) minimize
LUNs collisions with write I/Os, and (ii) even out the price of erasing
on every write, instead of putting all the burden on when garbage
collection runs. This works well on the current design, but is specific
to the default mapping algorithm.
This patch generalizes the erase path so that other mapping algorithms
can select an arbitrary line to be erased instead. It also gets rid of
the erase semaphore since it creates jittering for user writes.
Javier González [Mon, 26 Jun 2017 09:57:14 +0000 (11:57 +0200)]
lightnvm: pblk: expose max sec per write on sysfs
Allow to configure the number of maximum sectors per write command
through sysfs. This makes it easier to tune write command sizes for
different controller configurations.
Jens Axboe [Fri, 23 Jun 2017 15:18:54 +0000 (09:18 -0600)]
mtip32xx: fix up the checking for internal command failure
This fixes up two commits that have touched this driver. The
command status field is now a blk_status_t, so we can't check
for < 0 and we definitely can't assume it's holding -Exxxx error
values. All we care about here is whether ->status is zero or not.
Check for that, and remove the various attempts at smart error
reporting. Just log to dmesg what command failed, and the
blk_status_t value.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 2a842acab109 ("block: introduce new block status code type") Fixes: 3f5e6a35774c ("mtip32xx: convert internal command issue to block IO path") Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull in the fix for shared tags, as it conflicts with the pending
changes in for-4.13/block. We already pulled in v4.12-rc5 to solve
other conflicts or get fixes that went into 4.12, so not a lot
of changes in this merge.
Bart Van Assche [Wed, 21 Jun 2017 17:55:47 +0000 (10:55 -0700)]
blk-mq: Make it safe to quiesce and unquiesce from an interrupt handler
Since blk_mq_quiesce_queue_nowait() can be called from interrupt
context, make this safe. Since this function is not in the hot
path, uninline it.
Fixes: commit f4560ffe8cec ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 21 Jun 2017 17:55:46 +0000 (10:55 -0700)]
block: Fix off-by-one errors in blk_status_to_errno() and print_req_error()
This was detected by the smatch static analyzer.
Fixes: commit 2a842acab109 ("block: introduce new block status code type") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 21 Jun 2017 17:55:45 +0000 (10:55 -0700)]
block: Declare local symbols static
Avoid that building with W=1 causes the compiler to complain that
a declaration for bounce_bio_set and bounce_bio_split is missing.
References: commit a8821f3f32be ("block: Improvements to bounce-buffer handling") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Neil Brown <neilb@suse.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 21 Jun 2017 16:40:11 +0000 (09:40 -0700)]
block: Add fallthrough markers to switch statements
This patch suppresses gcc 7 warnings about falling through in switch
statements when building with W=1. From the gcc documentation: The
-Wimplicit-fallthrough=3 warning is enabled by -Wextra. See also
https://gcc.gnu.org/onlinedocs/gcc-7.1.0/gcc/Warning-Options.html.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 20 Jun 2017 23:56:13 +0000 (17:56 -0600)]
blk-mq: fix performance regression with shared tags
If we have shared tags enabled, then every IO completion will trigger
a full loop of every queue belonging to a tag set, and every hardware
queue for each of those queues, even if nothing needs to be done.
This causes a massive performance regression if you have a lot of
shared devices.
Instead of doing this huge full scan on every IO, add an atomic
counter to the main queue that tracks how many hardware queues have
been marked as needing a restart. With that, we can avoid looking for
restartable queues, if we don't have to.
Max reports that this restores performance. Before this patch, 4K
IOPS was limited to 22-23K IOPS. With the patch, we are running at
950-970K IOPS.
Fixes: 6d8c6c0f97ad ("blk-mq: Restart a single queue if tag sets are shared") Reported-by: Max Gurtovoy <maxg@mellanox.com> Tested-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:49 +0000 (11:15 -0700)]
blk-mq: Warn when attempting to run a hardware queue that is not mapped
A queue must be frozen while the mapped state of a hardware queue
is changed. Additionally, any change of the mapped state is
followed by a call to blk_mq_map_swqueue() (see also
blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues()).
Since blk_mq_map_swqueue() does not map any unmapped hardware
queue onto any software queue, no attempt will be made to run
an unmapped hardware queue. Hence issue a warning upon attempts
to run an unmapped hardware queue.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:48 +0000 (11:15 -0700)]
block: Constify disk_type
The variable 'disk_type' is never modified so constify it.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:47 +0000 (11:15 -0700)]
blk-mq: Document locking assumptions
Document the locking assumptions in functions that modify
blk_mq_ctx.rq_list to make it easier for humans to verify
this code.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:46 +0000 (11:15 -0700)]
block: Document what queue type each function is intended for
Some functions in block/blk-core.c must only be used on blk-sq queues
while others are safe to use against any queue type. Document which
functions are intended for blk-sq queues and issue a warning if the
blk-sq API is misused. This does not only help block driver authors
but will also make it easier to remove the blk-sq code once that code
is declared obsolete.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:45 +0000 (11:15 -0700)]
block: Check locking assumptions at runtime
Instead of documenting the locking assumptions of most block layer
functions as a comment, use lockdep_assert_held() to verify locking
assumptions at runtime.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:44 +0000 (11:15 -0700)]
block: Add a comment above queue_lockdep_assert_held()
Add a comment above the queue_lockdep_assert_held() macro that
explains the purpose of the q->queue_lock test.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:43 +0000 (11:15 -0700)]
blk-mq: Initialize .rq_flags in blk_mq_rq_ctx_init()
Initialization of blk-mq requests is a bit weird: blk_mq_rq_ctx_init()
is called after a value has been assigned to .rq_flags and .rq_flags
is initialized in __blk_mq_finish_request(). Initialize .rq_flags in
blk_mq_rq_ctx_init() instead of relying on __blk_mq_finish_request().
Moving the initialization of .rq_flags is fine because all changes
and tests of .rq_flags occur between blk_get_request() and finishing
a request.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:42 +0000 (11:15 -0700)]
block: Change argument type of scsi_req_init()
Since scsi_req_init() works on a struct scsi_request, change the
argument type into struct scsi_request *.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:41 +0000 (11:15 -0700)]
block: Make most scsi_req_init() calls implicit
Instead of explicitly calling scsi_req_init() after blk_get_request(),
call that function from inside blk_get_request(). Add an
.initialize_rq_fn() callback function to the block drivers that need
it. Merge the IDE .init_rq_fn() function into .initialize_rq_fn()
because it is too small to keep it as a separate function. Keep the
scsi_req_init() call in ide_prep_sense() because it follows a
blk_rq_init() call.
References: commit 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:40 +0000 (11:15 -0700)]
block: Introduce request_queue.initialize_rq_fn()
Several block drivers need to initialize the driver-private request
data after having called blk_get_request() and before .prep_rq_fn()
is called, e.g. when submitting a REQ_OP_SCSI_* request. Avoid that
that initialization code has to be repeated after every
blk_get_request() call by adding new callback functions to struct
request_queue and to struct blk_mq_ops.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:39 +0000 (11:15 -0700)]
block: Make request operation type argument declarations consistent
Instead of declaring the second argument of blk_*_get_request()
as int and passing it to functions that expect an unsigned int,
declare that second argument as unsigned int. Also because of
consistency, rename that second argument from 'rw' into 'op'.
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 20 Jun 2017 18:15:38 +0000 (11:15 -0700)]
blk-mq: Reduce blk_mq_hw_ctx size
Since the srcu structure is rather large (184 bytes on an x86-64
system with kernel debugging disabled), only allocate it if needed.
Reported-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 20 Jun 2017 20:22:01 +0000 (14:22 -0600)]
null_blk: add support for shared tags
Some storage drivers need to share tag sets between devices. It's
useful to be able to model that with null_blk, to find hangs or
performance issues.
Add a 'shared_tags' bool module parameter that. If that is set to
true and nr_devices is bigger than 1, all devices allocated will
share the same tag set.
Return EAGAIN if any of the following checks fail
+ i_rwsem is not lockable
+ NODATACOW or PREALLOC is not set
+ Cannot nocow at the desired location
+ Writing beyond end of file which is not allocated
If IOCB_NOWAIT is set, bail if the i_rwsem is not lockable
immediately.
IF IOMAP_NOWAIT is set, return EAGAIN in xfs_file_iomap_begin
if it needs allocation either due to file extension, writing to a hole,
or COW or waiting for other DIOs to finish.
Return -EAGAIN if we don't have extent list in memory.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Return EAGAIN if any of the following checks fail for direct I/O:
+ i_rwsem is lockable
+ Writing beyond end of file (will trigger allocation)
+ Blocks are not allocated at the write location
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
A new bio operation flag REQ_NOWAIT is introduced to identify bio's
orignating from iocb with IOCB_NOWAIT. This flag indicates
to return immediately if a request cannot be made instead
of retrying.
Stacked devices such as md (the ones with make_request_fn hooks)
currently are not supported because it may block for housekeeping.
For example, an md can have a part of the device suspended.
For this reason, only request based devices are supported.
In the future, this feature will be expanded to stacked devices
by teaching them how to handle the REQ_NOWAIT flags.
Find out if the I/O will trigger a wait due to writeback. If yes,
return -EAGAIN.
Return -EINVAL for buffered AIO: there are multiple causes of
delay such as page locks, dirty throttling logic, page loading
from disk etc. which cannot be taken care of.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
RWF_NOWAIT informs kernel to bail out if an AIO request will block
for reasons such as file allocations, or a writeback triggered,
or would block while allocating requests while performing
direct I/O.
RWF_NOWAIT is translated to IOCB_NOWAIT for iocb->ki_flags.
FMODE_AIO_NOWAIT is a flag which identifies the file opened is capable
of returning -EAGAIN if the AIO call will block. This must be set by
supporting filesystems in the ->open() call.
Filesystems xfs, btrfs and ext4 would be supported in the following patches.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
aio_rw_flags is introduced in struct iocb (using aio_reserved1) which will
carry the RWF_* flags. We cannot use aio_flags because they are not
checked for validity which may break existing applications.
Note, the only place RWF_HIPRI comes in effect is dio_await_one().
All the rest of the locations, aio code return -EIOCBQUEUED before the
checks for RWF_HIPRI.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
filemap_range_has_page() return true if the file's mapping has
a page within the range mentioned. This function will be used
to check if a write() call will cause a writeback of previous
writes.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 19 Jun 2017 02:21:08 +0000 (10:21 +0800)]
nvme: host: unquiesce queue in nvme_kill_queues()
When nvme_kill_queues() is run, queues may be in
quiesced state, so we forcibly unquiesce queues to avoid
blocking dispatch, and I/O hang can be avoided in
remove path.
Peviously we use blk_mq_start_stopped_hw_queues() as
counterpart of blk_mq_quiesce_queue(), now we have
introduced blk_mq_unquiesce_queue(), so use it explicitly.
Cc: linux-nvme@lists.infradead.org Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Tue, 6 Jun 2017 15:22:10 +0000 (23:22 +0800)]
Revert "blk-mq: don't use sync workqueue flushing from drivers"
This patch reverts commit 2719aa217e0d02(blk-mq: don't use
sync workqueue flushing from drivers) because only
blk_mq_quiesce_queue() need the sync flush, and now
we don't need to stop queue any more, so revert it.
Also changes to cancel_delayed_work() in blk_mq_stop_hw_queue().
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Tue, 6 Jun 2017 15:22:09 +0000 (23:22 +0800)]
blk-mq: clarify dispatch may not be drained/blocked by stopping queue
BLK_MQ_S_STOPPED may not be observed in other concurrent I/O paths,
we can't guarantee that dispatching won't happen after returning
from the APIs of stopping queue.
So clarify the fact and avoid potential misuse.
Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Tue, 6 Jun 2017 15:22:08 +0000 (23:22 +0800)]
blk-mq: don't stop queue for quiescing
Queue can be started by other blk-mq APIs and can be used in
different cases, this limits uses of blk_mq_quiesce_queue()
if it is based on stopping queue, and make its usage very
difficult, especially users have to use the stop queue APIs
carefully for avoiding to break blk_mq_quiesce_queue().
We have applied the QUIESCED flag for draining and blocking
dispatch, so it isn't necessary to stop queue any more.
After stopping queue is removed, blk_mq_quiesce_queue() can
be used safely and easily, then users won't worry about queue
restarting during quiescing at all.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sun, 18 Jun 2017 20:24:27 +0000 (14:24 -0600)]
blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue
It is required that no dispatch can happen any more once
blk_mq_quiesce_queue() returns, and we don't have such requirement
on APIs of stopping queue.
But blk_mq_quiesce_queue() still may not block/drain dispatch in the
the case of BLK_MQ_S_START_ON_RUN, so use the new introduced flag of
QUEUE_FLAG_QUIESCED and evaluate it inside RCU read-side critical
sections for fixing this issue.
Also blk_mq_quiesce_queue() is implemented via stopping queue, which
limits its uses, and easy to cause race, because any queue restart in
other paths may break blk_mq_quiesce_queue(). With the introduced
flag of QUEUE_FLAG_QUIESCED, we don't need to depend on stopping queue
for quiescing any more.
Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Tue, 6 Jun 2017 15:22:03 +0000 (23:22 +0800)]
blk-mq: introduce blk_mq_unquiesce_queue
blk_mq_start_stopped_hw_queues() is used implictly
as counterpart of blk_mq_quiesce_queue() for unquiescing queue,
so we introduce blk_mq_unquiesce_queue() and make it
as counterpart of blk_mq_quiesce_queue() explicitly.
This function is for improving the current quiescing mechanism
in the following patches.
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
NeilBrown [Sun, 18 Jun 2017 04:38:59 +0000 (14:38 +1000)]
block: don't check for BIO_MAX_PAGES in blk_bio_segment_split()
blk_bio_segment_split() makes sure bios have no more than
BIO_MAX_PAGES entries in the bi_io_vec.
This was done because bio_clone_bioset() (when given a
mempool bioset) could not handle larger io_vecs.
No driver uses bio_clone_bioset() any more, they all
use bio_clone_fast() if anything, and bio_clone_fast()
doesn't clone the bi_io_vec.
The main user of of bio_clone_bioset() at this level
is bounce.c, and bouncing now happens before blk_bio_segment_split(),
so that is not of concern.
NeilBrown [Sun, 18 Jun 2017 04:38:59 +0000 (14:38 +1000)]
block: remove bio_clone() and all references.
bio_clone() is no longer used.
Only bio_clone_bioset() or bio_clone_fast().
This is for the best, as bio_clone() used fs_bio_set,
and filesystems are unlikely to want to use bio_clone().
So remove bio_clone() and all references.
This includes a fix to some incorrect documentation.
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
NeilBrown [Sun, 18 Jun 2017 04:38:59 +0000 (14:38 +1000)]
bcache: use kmalloc to allocate bio in bch_data_verify()
This function allocates a bio, then a collection
of pages. It copes with failure.
It currently uses a mempool() to allocate the bio,
but alloc_page() to allocate the pages. These fail
in different ways, so the usage is inconsistent.
Change the bio_clone() to bio_clone_kmalloc()
so that no pool is used either for the bio or the pages.
Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by : Ming Lei <ming.lei@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
NeilBrown [Sun, 18 Jun 2017 04:38:59 +0000 (14:38 +1000)]
xen-blkfront: remove bio splitting.
bios that are re-submitted will pass through blk_queue_split() when
blk_queue_bio() is called, and this will split the bio if necessary.
There is no longer any need to do this splitting in xen-blkfront.
Acked-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
NeilBrown [Sun, 18 Jun 2017 04:38:58 +0000 (14:38 +1000)]
lightnvm/pblk-read: use bio_clone_fast()
pblk_submit_read() uses bio_clone_bioset() but doesn't change the
io_vec, so bio_clone_fast() is a better choice.
It also uses fs_bio_set which is intended for filesystems. Using it
in a device driver can deadlock.
So allocate a new bioset, and and use bio_clone_fast().
Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Javier González <javier@cnexlabs.com> Tested-by: Javier González <javier@cnexlabs.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
NeilBrown [Sun, 18 Jun 2017 04:38:58 +0000 (14:38 +1000)]
pktcdvd: use bio_clone_fast() instead of bio_clone()
pktcdvd doesn't change the bi_io_vec of the clone bio,
so it is more efficient to use bio_clone_fast(), and not clone
the bi_io_vec.
This requires providing a bio_set, and it is safest to
provide a dedicated bio_set rather than sharing
fs_bio_set, which filesytems use.
This new bio_set, pkt_bio_set, can also be use for the bio_split()
call as the two allocations (bio_clone_fast, and bio_split) are
independent, neither can block a bio allocated by the other.
NeilBrown [Sun, 18 Jun 2017 04:38:58 +0000 (14:38 +1000)]
drbd: use bio_clone_fast() instead of bio_clone()
drbd does not modify the bi_io_vec of the cloned bio,
so there is no need to clone that part. So bio_clone_fast()
is the better choice.
For bio_clone_fast() we need to specify a bio_set.
We could use fs_bio_set, which bio_clone() uses, or
drbd_md_io_bio_set, which drbd uses for metadata, but it is
generally best to avoid sharing bio_sets unless you can
be certain that there are no interdependencies.
So create a new bio_set, drbd_io_bio_set, and use bio_clone_fast().
Also remove a "XXX cannot fail ???" comment because it definitely
cannot fail - bio_clone_fast() doesn't fail if the GFP flags allow for
sleeping.
NeilBrown [Sun, 18 Jun 2017 04:38:58 +0000 (14:38 +1000)]
rbd: use bio_clone_fast() instead of bio_clone()
bio_clone() makes a copy of the bi_io_vec, but rbd never changes that,
so there is no need for a copy.
bio_clone_fast() can be used instead, which avoids making the copy.
This requires that we provide a bio_set. bio_clone() uses fs_bio_set,
but it isn't, in general, safe to use the same bio_set at different
levels of the stack, as that can lead to deadlocks. As filesystems
use fs_bio_set, block devices shouldn't.
As rbd never stacks, it is safe to have a single global bio_set for
all rbd devices to use. So allocate that when the module is
initialised, and use it with bio_clone_fast().
NeilBrown [Sun, 18 Jun 2017 04:38:58 +0000 (14:38 +1000)]
block: Improvements to bounce-buffer handling
Since commit 23688bf4f830 ("block: ensure to split after potentially
bouncing a bio") blk_queue_bounce() is called *before*
blk_queue_split().
This means that:
1/ the comments blk_queue_split() about bounce buffers are
irrelevant, and
2/ a very large bio (more than BIO_MAX_PAGES) will no longer be
split before it arrives at blk_queue_bounce(), leading to the
possibility that bio_clone_bioset() will fail and a NULL
will be dereferenced.
Separately, blk_queue_bounce() shouldn't use fs_bio_set as the bio
being copied could be from the same set, and this could lead to a
deadlock.
So:
- allocate 2 private biosets for blk_queue_bounce, one for
splitting enormous bios and one for cloning bios.
- add code to split a bio that exceeds BIO_MAX_PAGES.
- Fix up the comments in blk_queue_split()
Credit-to: Ming Lei <tom.leiming@gmail.com> (suggested using single bio_for_each_segment loop) Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
projects / karo-tx-linux.git / log